Switching device



May 5, 1936. H. J. L. FRANK v2,039,589

SWITCHING DEVICE Filed Oct. 29, 1954 3 Sheets-Sheet 1 lla ATTORNEY.

5 Sheets-Sheet 2 INVENTOR. Ma@

ATTORNEY.

H. J. l.. FRANK swITcHING DEVICE Filed Oct. 29,v 19:54

ma m

May 5, 1936.

Q r4 @HufQ/a W May 5, 1935- H. J. FRANK 2,039,589

'SWITCHING DEVICE Filed Oct. 29, 1934 3 Sheets-Sheet 5 INVENTOR.

, ATTORNEY.

Patented May ,5, 1936 UNITED STATES aosasss swlrcnmo. nevica 'Harrison J. L. Frank, Detroit, man.,

Bulldog Electric Products Company, Mich., a corporation of West Virginia assigner to mma,

Application october zo, 1934, serial No. '150,492

' s claim.` (ci. zoo-13s) This application relates to switching devices and discloses two similar switching devices, each comprising in general a sheet metal box contain- 'ing a cup-shaped receptacle exposed through a '5 .hole in a front of the box for insertion thereinto and withdrawal therefrom of a fused switch` plug or head cooperating with said receptacle.

Objects and features of the inventions of this application will best be understood upon reference tothe appended drawings which disclose lilubodiments of the inventions. In these draws, Fig. 1 is a cutaway front View of a switching device as mounted against a vertical wall; l5- Fig. 2 is a section thereof;

3 is a partial section at right angles to the view of Fig. 2, with the plug shown in the circuitbreak position; y v

Figs.' 4, and 5 show the plug nd receptacle parts per se, in two diierent re 'tive positions;

Fig. 6 is a partial section like Fig. 3 but showing a differently formed device.

Referring to Figs. 1-5 of the drawings, it will` be seen that there is there shown av switching device including a sheet metal box I0 having a iiat front il mounted on hinges Ila, and having knockouts (not shown) for providing cable entrance into the interior thereof, the box being shown as provided with three pairs ofv line and ad load conductors I2. I

, Disposed within the box and shielded there'-l from by insulation sheet .i4 on the back thereof and secured 4thereto by screws Ila is a receptacle I5. The latter is of insulation material, and is generally cup-shaped, being provided with ledges- I6, on which are disposed four stationary con'- tacts Il, these being secured in place byv screws Il which have binding nuts lthereon for physically and electrically connecting two pairs of the conductors I2 to the contacts l1. Since the third pair of conductors is to form a neutral line, the conductors of this pair are mutually connected by means of a neutral strap 2li disposed on the back of the receptacle andsecure'd thereto and connecting the binding screws 2 i, these having binding nuts 22 thereon for connecting the conductors of the third pair to the strap, the latter being. in electrical contact with the back of the box I l, substantially as shown in Fig. 3. 50 For cooperating with the receptacle there is Aprovided a fused plug. The lattercompris a plug body 24 of insulation provided -with a handle 25 which vprojects through an opening 26 in the front vIl sc as to be accessible fromv outside the device when the front closes the box. In-a wall of the plug are two relatively isolated and barriered depressions or sockets 21 containing threaded socket shells for the reception'of plug fuses 29 of conventional character. A tip contact 30 in each socket shell is connected by a 5 center screw 3l to a contact prong 32 on the wall of the plug opposite the socketed wall aforementioned. Eachshell is electrically connected by a rivet 33 to a contact prong disposed against the socketed wall of the plug and projecting l0 downwardly therefrom through a slot I5 thereof. The contact prongs l2- 34 are aligned with one another in pairs and connect the mutually alignedcontacts I1 of the receptacle thru the socket shells and fuses. The pairs of prongs are 16 Y relatively barriered by barrier grooves and ribs 30 on walls of the plug.

Secured to an end wall of the box I0 is a spring lug 38 which projects upwardly through a` hole in the front cover I I to act as a latchv there- 20.-

i'or, the spring lug for this purpose beingprovided with a deformation I9. The spring lug for locking the box when the front is closed has an aperture 4| for the reception of a padlock or other locking device.

The sockets 21 of the plug are formed with test f' slots I3 for the reception of test leads which may be inserted into the sockets for engagement with the socket shells therein, through the hole 28 of the front, even when the latter is closed and when the plug is in the receptacle. A

Operation and uses of the switching device will now be described. InI normal use, the parts occupy the position shown in Fig. 2, and the circuits between the conductors of the pairs are closed through the prongs 32 and 34, the tip contacts and shells of the socket shells, and the plug fuses. v

When it is desired to break the circuit. for normal switching or for fuse renewal, even when 40 the front I iis closed, this may be done very conveniently merely by pulling the plug out of the vreceptacle to the plug-out position of Fig. 3.

Lugs 48 formed on the plug engage the under surface ofthe front H to prevent complete with- 45. drawal of the plug from the device, partial withdrawal being suilicient for circuit breaking, or fuse renewal. The operation of circuit breaking exposes the sockets of the plug and the fuses therein, andpermits fuse renewal, the operation 50 of fuse renewal being interlocked to the operation of plug withdrawal so that the circuits are broken before fuse renewal can be effected. It will be observed that the plug is held in circuit breaking position by the frictioned engageaction and carrying fuses in such a. way that they may be exposed without requiring the carrier to be disassociated with respect to the base, and having a handle outside the casing whereby the carrier may be pushed towards or pulled away from the base, the carrier being so formed that lwhen it is associated with the base it debars access to live parts of the device and being formed to be removable from the base and being'capable of association therewith in circuit closing or circuit opening position, fuse exposure being possible only when the circuit is'opened by pulling the carrier away from the base, the devicejncluding personally controllable means operable optionally for preventing the carrier completely from being removed from the device and exposing live contacts of the device, while permitting it to be pulled away from theA base for switching and fuse exposure or for permitting the carrier to be disassociated from the base, access to live parts being attained only when the cover is open or the'carrier is not associated with the base, the cover being openable even when the carrier is in circuit closing association with the base.

5. A switching device oiV the character that lcomprises a"casing having a main cover provided with an opening and containing a switch including', a base within the casing behind the opening, a fuse carrier reciprocable through vthe opening towards and away from the base for switching actionland carrying fuses in such a way that they may be exposed without requiring the carrier to be disassociated with respect to .the base, and having a handle outside the casing wherebythe carrier may be pushed towards or pulled away from thel base, the carrier being so formed that when it is associated with the base it debars access to live parts of thedevice and being formed to be removable from the base and being capable of association therewith in circuit closing or circuit opening position, fuse exposure being possible only when the circuit is opened by pulling the carrier away from'the basei the device including personally controllable means operable optionally for preventing the carrier completely from being removed from the device and exposing live contacts oil the device, while permitting it to be pulled away from the base for switching and fuse exposure or lfor permitting the carrier to be disassociated from the base, access to live parts being attained only when the cover is open or the carrier is not associated with the base, the cover being openable even when the carrier is in circuit closing association with the base, and means for sealing the switch in open circuit condition with the carrier in association with the base.

HARRISON J. L. FRANK. 

